(TRENTON) – A 3-year-old horse from Gloucester County was euthanized on October 20 after contracting Eastern Equine Encephalitis (EEE), a serious, mosquito-borne illness in horses.

“With an increase in the state’s mosquito population due to rain storms in the last couple of months, horse owners must be vigilant in protecting their animals from diseases spread by mosquitoes,” said New Jersey

Secretary of Agriculture Douglas H. Fisher. “Horse owners should contact their veterinarians to have their animals vaccinated against these illnesses.”

This deadly disease is easily prevented by vaccination. Effective equine vaccines for EEE and another mosquito-borne disease, West Nile Virus (WNV) are available commercially. Horse owners should contact their veterinarians if their horses are not already up-to-date on their vaccinations against both EEE and West Nile virus. The Gloucester County stallion’s vaccination status against EEE is unknown with no report of vaccination in 2011.

EEE causes inflammation of the brain tissue and has a significantly higher risk of death in horses than West Nile Virus infection. West Nile virus is a viral disease that affects horses’ neurological systems. The disease is transmitted by mosquito bite. The virus cycles between birds and mosquitoes with horses and humans being incidental hosts. EEE infections in horses are not a significant risk factor for human infection because horses (like humans) are considered to be "dead-end" hosts for the virus.

Earlier this month, the first case of West Nile Virus in a horse was reported in Monmouth County. The 11-year-old mare was treated for the disease.

The New Jersey Department of Environmental Protection reports that the exceedingly high levels of precipitation experienced statewide due to Hurricane Irene and subsequent rainstorms resulted in much higher than normal mosquito populations. They said the immense amount of floodwater throughout the state created habitat for those species of mosquitoes which utilize semi-permanent, standing water for larval development.

In 2010, New Jersey had one case of EEE and two cases of equine WNV. All three animals were euthanized.